Sunday, October 27, 2013
Five Phony Public Health Scares
Activist misinformation harms Americans
Health activists, nutrition nannies, medical paternalists, and just plain old quacks regularly conjure up menaces that are supposedly damaging the health of Americans. Their scares range from the decades-long campaign against fluoridation to worries that saccharin causes cancer to the ongoing hysteria over crop biotechnology. The campaigners' usual "solution" is to demand that regulators ban the offending substance or practice. Here are five especially egregious examples of activist misinformation.
1. Americans should consume no more than 1,500 milligrams of sodium per day, in order to reduce everybody's risk of heart disease, strokes, and high blood pressure.
You hear this one all the time. The American Heart Association recommends consuming less than 1,500 milligrams of sodium per day. A June 2013 report by the Center for Science in the Public Interest asserted, "Immediately reducing average sodium consumption levels to between 2,200 mg to 1,500 mg per day would save about 700,000 to 1.2 million lives over 10 years." These nutrition nannies have been urging the U.S. government to lower the upper limit of daily recommended sodium intake to just two-thirds of a teaspoon of salt.
But a May 2013 study by the Institute of Medicine calls those longstanding recommendations into question. Contrary to years of anti-salt dogma, consuming less than 2,300 milligrams of sodium a day may actually harm people suffering from congestive heart failure. There was also "no evidence for benefit and some evidence suggesting risk of adverse health outcomes" if the person with a low-salt diet has diabetes, chronic kidney disease, or pre-existing cardiovascular disease.
"The evidence on health outcomes," the report concluded, "is not consistent with efforts that encourage lowering of dietary sodium in the general population to 1,500 milligrams per day."
2. Vaccines cause autism.
In 1998 the British researcher Andrew Wakefield claimed in The Lancet that he had identified an association between vaccination against measles, mumps, and rubella (MMR) and the onset of autism. Thus was launched one of the more destructive health scares of recent years, in which tens of thousands of frightened parents refused to have their children vaccinated. Anti-vaccine cheerleaders such as the actress Jenny McCarthy fanned those fears.
Years of research and numerous studies have thoroughly debunked this scare. For example, the Institute of Medicine issued a 2011 report, "Adverse Effects of Vaccines," that found no association between MMR vaccination and autism. The Centers for Disease Control and Prevention agrees that "there is no relationship between vaccines containing thimerosal and autism rates in children." The Lancet finally retracted the infamous Wakefield study in 2010. Also in 2010, Britain's General Medical Council banned Wakefield from the practice of medicine after concluding that his paper had been not just inaccurate but dishonest.
3. Cellphone use causes cancer.
The fear here is that radio frequency waves emitted by cellular phones are associated with higher risk of various brain cancers. One anecdotal report even suggested that women who secreted their cellphones in their bras were more likely to get breast cancer.
It is true that in 2011 the hyper-precautionary International Agency for Research on Cancer classified cellphones as a "possible carcinogen." But as a somewhat snarky response in the Journal of Carcinogenesis pointed out, the agency classifies coffee and pickles as possible carcinogens, too. Meanwhile, the National Cancer Institute flatly states that "to date there is no evidence from studies of cells, animals, or humans that radiofrequency energy can cause cancer." A 2012 comprehensive review of studies in the journal Bioelectromagnetics found "no statistically significant increase in risk for adult brain or other head tumors from wireless phone use."
4. High fructose corn syrup is responsible for the obesity "epidemic."
This particular scare was launched by a 2004 article in the American Journal of Clinical Nutrition, which noted, "The increased use of HFCS in the United States mirrors the rapid increase in obesity." The authors pointed out that American consumption of HFCS had increased by more than 1,000 percent between 1970 and 1990, and they estimated that Americans consumed an average of 132 kilocalories of HFCS per day. Digesting fructose, they suggested, failed to send signals to the brain to tell people to stop eating.
Since this scare was unleashed, a lot of research has investigated many different hypotheses about how HFCS might be worse for people than table sugar (sucrose). Most have turned up nothing significant.
A 2012 review article in the journal Advances in Nutrition summarized this research: "a broad scientific consensus has emerged that there are no metabolic or endocrine response differences between HFCS and sucrose related to obesity or any other adverse health outcome. This equivalence is not surprising given that both of these sugars contain approximately equal amounts of fructose and glucose, contain the same number of calories, possess the same level of sweetness, and are absorbed identically through the gastrointestinal tract." Another 2012 review article, in the Journal of Obesity, concluded, "In the past decade, a number of research trials have demonstrated no short-term differences between HFCS and sucrose in any metabolic parameter or health related effect measured in human beings including blood glucose, insulin, leptin, ghrelin and appetite."
So if HFCS is not to blame for the fattening up of Americans, what is? How about pigging out? The U.S. Department of Agriculture reports that in 1970 Americans consumed an average of 2,169 calories per day. In 2010, the figure was about 2,614. Sweeteners such as sugar and HFCS provided only 42 of this 445-calorie increase.
5. Exposure to trace amounts of synthetic chemicals is a major cause of cancer.
Rachel Carson's passionate 1962 bestseller Silent Spring warned that we "are living in a sea of carcinogens." More recently, a 2010 report issued by the President's Cancer Panel declared, "The true burden of environmentally induced cancers has been grossly underestimated."
But is that so? As the American Cancer Society's Cancer Facts and Figures 2013 notes, "Exposure to carcinogenic agents in occupational, community, and other settings is thought to account for a relatively small percentage of cancer deaths-about 4% from occupational exposures and 2% from environmental pollutants (man-made and naturally occurring)." The same group rejected the President's Cancer Panel's conclusion as well, arguing that it "does not represent scientific consensus."
In fact, at the same time that human ingenuity has been generating all these useful synthetic compounds, both cancer incidence and death rates have been falling. While cancer remains the second leading cause of death in the United States, a 2012 report by the National Cancer Institute confirms that overall cancer death rates continue to decline, and that over the past decade the incidence of cancer continues to fall for men while holding steady for women.
Once a bogus health alarm has been launched, more careful researchers must waste years and tens of millions of dollars battling the misinformation. In the meantime, worried Americans actually harm their health by refusing to get their kids vaccinated, or squander their money on such items as "chemical-free" products.
Scaremongering, unfortunately, can be both lucrative and a source of gratifying media attention, so it's not likely to go away anytime soon.
Posted by jonjayray at 12:22 AM